Lower control arms loosen after launch?

[JPs2013GT500]

I have the non-adjustable BMR lower control arm (TCA019) with relocation bracket (CAB005). I'll torque the three bolts down and all is great for a while. It feels amazing, it rides wonderfully (dare I say better than stock), feels tight & well planted, etc..

However, after the very first moderate launch (really anything that makes the rear squat decently) the car feels completely different. It bounces around a lot (think cut spring low-rider), wheel hops a lot, will lose traction easily, etc. While the bolts don't seem loose, I re-torque them anyway. All is great again till the next launch.

Last week I took the bolts out, applied a touch of thread lock, and reinstalled. Took it out tonight and as usual it was great until that first launch.

My torque wrench is pretty old. so I may pick up a new one just to see if mine is out of calibration. Besides that, anyone else experience something like this or know what I may be doing wrong?

Should I weld the relocation brackets? Would an aftermarket upper control arm to help prevent this?

 

[StangsfeverFOX]

Torque them with he rear suspension loaded, not hanging . Other than that you wrench may be screwed up..

 

[beau t]

are you using blue loctite, if so try using red it has more holding strength and as stated above loaded and torque wrench check

 

[StangsfeverFOX]

The relocation brackets used nylon nuts . Or atleast 4 sets if installed did , another thought, not sure if you have them or not

 

[JPs2013GT500]

I 'lift' it with race ramps so the suspension is loaded whenever I tighten the bolts.

The hardware I used also included those nylon nuts.

I hit them today with a new torque wrench and they needed tightening to reach the required 129 lb/ft. So, either my old torque wrench is out of calibration (probably) or the bolts loosened on their own.

Drove it a little today after tightening them with the new torque wrench but I haven't had the opportunity to re-check the bolts yet. It feels like they haven't backed off so far. Time will tell.

 

[Catmonkey]

With a poly bushing or rod end, the control arms and brackets don't need to be tightened at ride height. Poly bushings and rod ends move freely on articulation of these components. This is not the case with bonded rubber bushings which should be tightened at ride height.

 

[Cman01]

I've had to retorque mine a few times once my control arms went on a few years ago. I believe Ford wants you to put new bolts in when you remove them but I didn't bother I reused my bolts with thread locker and after retorquing them those few times after first install they've kept the torque.

However, before every season when I bring the car out or before an event that I'm going to run the car in (drag or lapping) I check them and they are tight (torque wrench clicks right at 129 ft./lbs without really moving the handle) and yes rear suspension is loaded when checking.

Tony

 

[JPs2013GT500]

Small update. I guess my next step is to replace the bolts and/or spot weld these brackets. The passenger side seems good now, but the driver side bracket bolts continue to loosen after I retorque them.

On my last attempt to tighten them I said screw it and used my impact driver...still loosened over time. So, if they weren't stretched before, I'm sure they are now.

Due to this issue I seem to spend quite a bit of quality time under the rear of this car. I've noticed the reservoir on the shocks looks like they are leaking (stains & the yellow paint bubbling off).

The car does ride rather harshly. Makes me wonder if the shocks are damaged (lowered car) and perhaps that's putting some extra stress on these brackets/bolts?

Car has 19,1xx miles at this point, been on lowered springs since 6k or so.